Hydraulic Steering - 2006 Harris Float Boat - Mercury 150 4-Stroke Verado Supercharger

[Lake Murray]

I purchased this pontoon used a month ago. Never had hydraulic steering. Live on Lake Murray in Chapin, S. C. Been out several times with this pontoon. Last time out the steering was strange. When I would turn to the right it took more turns than I expected. Then when I decided to straighten out it was again more turns than I was used to on any boat that I had ever had. Of course, I had never had hydraulic steering. So, I find myself turning and turning the steering wheel more times than I want to go in one direction. I finally found the place where I can put the fluid into the hydraulic system. It was located behind the the windshield in a pop up compartment. I just unscrewed the cap and this is where the fluid goes. My question is what type of fluid do I put in. I was told Power steering fluid, then brake fluid. One person recommended mercon transmission fluid. I know nothing about what kind I need, but, before I do what is needed, I need the advise of someone on this board to give me some good advice.

Right above the cap that I unscrew, there is a Part # and the Word Quicksilver. I know Quicksilver is a name brand for oil and other fluids. I pulled up the part # and it was a part for the hydraulic system. Anyway, I want to go to the parts store in the morning and buy whatever I need to buy to put into the system. Could someone out there please advice me as to what I need to purchase. Thanks (If there is anything I need to do before I put in the fluid I would also like to know that also)

[steve1313]

You want hydraulic fluid. Google hydraulic fluid for boat steering and you'll see several brands, etc. If you saw a Quicksilver part # it was probably for this. https://www.wholesalemarine.com/quicksi ... gKep_D_BwE



Also, here's a good article about the system.
https://www.boatus.com/magazine/2014/fe ... eering.asp

[jrolin1]

Steve gave you good links to explain the system. Without a leak it should not need fluid regularly. So follow the steps in the second link to troubleshoot. It could be a very slow leak. Welcome to the site. I am on the Lexington side of the lake.

[Lake Murray]

Thanks Steve as I am new to Hydraulic Steering System. I will get the fluid and hope that takes care of the wandering steering. Also, thanks go out to 'jrolin1'. This gentleman lives on the same lake as me but is on the Lexington side of the lake as I am on the Chapin side.

Thanks again to the both of you........

Rick

[gerard143]

Seastar has quality steering fluid. They are the best in the biz. The pump (unit steering wheel is connected to) determines how many turns lock to lock. Different model numbers are generally sold with more or less turns required. This of course is assuming no air in your lines.

How many turns are we talking here?

[Liquid Asset]

This is what my verado steering pump says right on it!

Screenshot_20200615-203850.png (1.84 MiB) Viewed 11204 times

[Horsepen]

LA, looks like yours is Mercury’s power steering. I think he is referring to a Sea Star hydraulic steering, not an engine or externally powered system like yours. And to the OP, off hand I don’t remember the mil spec number for the Sea Star brand of fluid, but it should be on Sea Star’s website. Any hydraulic fluid/oil with that same mil spec number will work just fine. Sea Star also says that in a pinch one can use automotive power steering fluid and many people do. I have not. I use fluid that carries that mil spec number.

[Liquid Asset]

LA, looks like yours is Mercury’s power steering. I think he is referring to a Sea Star hydraulic steering, not an engine or externally powered system like yours. And to the OP, off hand I don’t remember the mil spec number for the Sea Star brand of fluid, but it should be on Sea Star’s website. Any hydraulic fluid/oil with that same mil spec number will work just fine. Sea Star also says that in a pinch one can use automotive power steering fluid and many people do. I have not. I use fluid that carries that mil spec number.

I know most verados came standard with the mercury power assist, and with a quick silver ( mercury) part number mentioned i assumed it was what he had. I have heard of some verados without it but thought it only the 135 HP. Sea star is made by teleflex and probably wouldn't have a quick silver part number.

Looks like a situation where a bit more info would nail down the correct answer!